Acta Agrestia Sinica ›› 2014, Vol. 22 ›› Issue (3): 493-501.DOI: 10.11733/j.issn.1007-0435.2014.03.010

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Research on Key Greenhouse Gas Fluxes across Alpine Steppe, Alpine Meadow and Swamp Meadow in Nam Co, Tibetan Plateau

Tenzin-tarchen1, Xuri2, WEI Xue-hong1, WEI Da2, LIU Yong-wen2, WANG Ying-hong3   

  1. 1. Agricultural and Animal Husbandry College of Tibet University, Nyingchi, Tibet 860000, China;
    2. Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China;
    3. Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
  • Received:2013-08-19 Revised:2013-10-21 Online:2014-06-15 Published:2014-06-04

西藏纳木错高寒草原、高寒草甸和沼泽化草甸主要温室气体通量对比研究

旦增塔庆1, 旭日2, 魏学红1, 魏达2, 刘永稳2, 王迎红3   

  1. 1. 西藏大学农牧学院, 西藏 林芝 860000;
    2. 中国科学院青藏高原研究所, 北京 100101;
    3. 中国科学院大气物理研究所, 北京 100029
  • 通讯作者: 旭日
  • 作者简介:旦增塔庆(1989- ),男,藏族,西藏拉萨人,硕士研究生,从事高寒草地生态学研究,E-mail:tarchentenzin@gmail.com;
  • 基金资助:

    国家自然科学基金(40975096)(41175128);中国科学院科技先导专项(XDA05020402)(XDA05050404-3-2)资助

Abstract:

The alpine grassland of Tibetan Plateau accounts for 40% of natural grassland in China. It is, therefore, important to qualify the greenhouse gas fluxes of the alpine grassland and their driving factors. Observations of ecosystem respiration, CH4 and N2O fluxes across alpine steppe, alpine meadow and swamp meadow were conducted using static chamber and gas chromatograph method in the Nam Co region of Tibetan Plateau. One growing season's measurement showed that the ecosystem respiration of alpine steppe and meadow were 283.7±14.4 mg·m-2·h-1 and 275.7±20.6 mg·m-2·h-1, respectively, and both were significantly lower than that of swamp meadow (591.6±53.2 mg·m-2·h-1), which was rich in soil organic carbon. Both alpine steppe and meadow were sinks of CH4 (-84.9±7.6 and -39.2±4.6 μg·m-2·h-1, respectively), while the swamp meadow was a resource of CH4 (149.2±34.2 μg·m-2·h-1). All three ecosystems were a resource of N2O. The emissions of N2O during growing season were 7.3±2.8, 3.0±1.1 and 2.2±4.3 μg·m-2·h-1, respectively. Comparison of CH4 flux among three grassland types indicated that the spatial-temporal variation of CH4 flux depended on the soil moisture. The swamp meadow with more than 30% soil moisture contents was a resource of CH4, while both alpine steppe and meadow with less than 30% soil moisture contents were the sinks of CH4 and the strength of the sink decreased with soil moisture increasing during growing season.

Key words: Alpine steppe, Alpine meadow, Swamp meadow, Ecosystem respiration, CH4 flux, N2O flux

摘要:

青藏高原高寒草地占我国天然草地的40%,研究其温室气体源汇强度及驱动因子具有重要意义。采用静态箱-气相色谱法,在西藏纳木错地区开展高寒草原、高寒草甸和沼泽化草甸的生态系统呼吸、CH4和N2O通量观测,生长季内的观测表明:高寒草原和高寒草甸生态系统呼吸分别为(283.7±14.4) mg·m-2·h-1和(275.7±20.6) mg·m-2·h-1,低于有机质丰富的沼泽化草甸,为(591.6±53.2) mg·m-2·h-1。高寒草原和高寒草甸均是CH4的汇,其生长季均值分别为(-84.9±7.6) μg·m-2·h-1和(-39.2±4.6) μg·m-2·h-1;而沼泽化草甸是CH4的源其均值为(149.2±34.2) μg·m-2·h-1。高寒草原、高寒草甸和沼泽化草甸均为N2O的源,生长季排放量分别为(7.3±2.8),(3.0±1.1)和(2.2±4.3) μg·m-2·h-1。土壤水分总体控制着高寒草地CH4通量的时空变化,在土壤水分含量约大于30%的沼泽化草甸表现为CH4的排放源,而在土壤水分含量低于30%的高寒草原和草甸表现为CH4的汇;生长季水分含量越高,对CH4的吸收越弱。

关键词: 高寒草原, 高寒草甸, 沼泽化草甸, 生态系统呼吸, CH4通量, N2O通量

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